Influence of orthodontic intrusion on pulpal vitality of previously traumatized maxillary permanent incisors

Introduction: Dental trauma seems to increase a patient's susceptibility to complications during orthodontic treatment. However, no previous investigation has examined the influence of orthodontic intrusion on pulpal vitality of traumatized maxillary permanent incisors. Methods: Pulpal condition was examined clinically and radiologically after orthodontic intrusion of previously traumatized (OT group) and nontraumatized teeth (O group), and after previous dental trauma without orthodontic treatment (T group). Inclusion criteria for the OT and O groups were Class II Division 1 malocclusion with deep bite and orthodontic intrusion of the maxillary incisors, no extractions of maxillary teeth, and no additional lateral tooth movement of the maxillary incisors. All teeth in the OT group had a positive sensitivity test before orthodontic therapy. Results: Teeth in the OT group, and especially those with severe periodontal injuries, showed a significantly higher frequency of pulp necrosis than teeth in the O and T groups. The occurrence of pulp necrosis was significantly higher in lateral than in central incisors. Conclusions: Traumatized maxillary incisors, and especially lateral incisors, with severe periodontal injuries have a higher susceptibility to pulp necrosis during orthodontic intrusion than nontraumatized teeth.